The Fast Moiré Interferometry method (FMI) is based on the combination of structured light projection and a phase-shift method for extracting, from an image of an object, 3D information about the object. FIG. 1 presents an example of a FMI system that enables such method.
As illustrated in FIG. 1, the FMI method is based on detecting light diffused by the inspected object. Structured light is projected on the object along a projection axis that is inclined by an angle θ with respect to the detection axis and diffused light along the detection axis, which is substantially normal to the surface of the object, is measured to provide an image of the object. But, in the case of reflection objects, the structured light projected on the object is in majority reflected along a direction which corresponds to the specular reflection of the projected light (like a mirror), and which does not correspond to the detection axis of FIG. 1. Therefore there is no (or very little) light directed toward the camera, what makes the inspection of such shiny object very difficult.
Thus there is a need for a FMI system and method for the 3D imaging of reflecting objects.